This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for INVEST-REGISTRY: Minimally Invasive Endoscopic Surgical Treatment With Apollo/Artemis in Patients With Brain Hemorrhage (NCT02661672), a na na study. The primary outcome is Number of Participants With Modified Rankin Score (mRS) ≤ 3 or mRS > 3.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02661672 |
| Phase | NA |
| Condition | Intracranial Hemorrhage |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 38 |
| Arms in the primary outcome | n/a |
| Lead sponsor | J. Mocco |
| Results posted | Yes |
2. Clinical Question
Population
Adults with supratentorial brain hemorrhage who did not qualify for the concurrent INVEST Feasibility randomized controlled trial at active INVEST centers. The registry enrolled 38 participants with intracranial hemorrhage. One participant was lost to follow-up after 1 month.
Intervention
Best medical management plus minimally invasive endoscopic surgery for clot evacuation using the Apollo or Artemis System. The registry describes the Apollo Device and Artemis Device as the devices used for this treatment.
Comparator
There was no separate control group in this single-group registry. The record does not describe a like-for-like comparison between device treatment and another treatment group.
Primary question
The primary endpoint classifies global disability at 180 days using the modified Rankin Score (mRS), separating participants with mRS ≤ 3 from those with mRS > 3. The registry objective was to provide additional safety, technical outcomes and clinical outcomes data for this surgical approach. The posted record does not report the number of participants in either primary endpoint category, so it does not establish the observed distribution of 180-day disability.
3. Trial Design
INVEST-REGISTRY (NCT02661672) is described as a prospective multicenter registry of minimally invasive endoscopic surgical treatment with Apollo or Artemis in patients with brain hemorrhage. The record lists the study as completed, with a start date of 2016-10-14 and a primary completion date of 2022-11-16. Enrollment was 38.
The registry has a single-group model and no masking. Allocation and phase are listed as NA. Participants received best medical management for intracranial hemorrhage plus minimally invasive endoscopic surgery and use of the Apollo or Artemis System for clot evacuation. The registry objective focused on adults with supratentorial brain hemorrhage who did not qualify for the concurrent INVEST Feasibility randomized controlled trial at active INVEST centers.
Because there is one treatment group and no randomized comparison, outcomes in this registry cannot be read as a direct estimate of the difference between surgery and an alternative treatment. The record itself cautions that the arms are not a like-for-like control comparison; the registry has no separate control arm. Participant outcomes can describe what was recorded among those enrolled, but the design does not isolate the effect of the procedure from other influences on outcomes.
The record lists Modified Rankin Score at 30 days and 90 days, length of hospital stay, and the number of participants requiring VPS among secondary outcomes. It lists 8 outcome measures and 0 analyses. Details of the protocol beyond the stated registry objectives and outcomes, including the statistical plan, are not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Patients With Brain Hemorrhage |
|---|---|
| STARTED | 38 |
| COMPLETED | 33 |
| NOT COMPLETED | 5 |
Reasons for not completing this period:
| Reason | Patients With Brain Hemorrhage |
|---|---|
| Lost to Follow-up | 1 |
| Death | 4 |
Analysis population for the primary outcome, as defined in the registry: one participant lost to follow-up after 1 month.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Patients With Brain Hemorrhage |
|---|---|---|
| Participants analysed | 38 | |
| Age, Continuous | years | 63.5 (24 to 86) |
| Sex: Female, Male: Female | Participants | 16 |
| Sex: Female, Male: Male | Participants | 22 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 8 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 30 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 4 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 16 |
| Race (NIH/OMB): White | Participants | 15 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 3 |
| Tobacco use: Never smoked | Participants | 23 |
| Tobacco use: Previously smoked (quit > 6 months ago) | Participants | 6 |
| Tobacco use: Currently smoking (or quit within the last 6 months) | Participants | 9 |
| Cocaine or methamphetamine use | Participants | 4 |
| On anticoagulant therapy | Participants | 6 |
| On antiplatelet therapy | Participants | 11 |
| On NSAID therapy | Participants | 0 |
| On antihypertensive therapy | Participants | 22 |
| Medical comorbidities: Diabetes | Participants | 6 |
| Medical comorbidities: Hypertension | Participants | 28 |
| Medical comorbidities: Other cardiovascular disease | Participants | 0 |
| Location of intracerebral hemorrhage: Deep | Participants | 18 |
| Location of intracerebral hemorrhage: Lobar | Participants | 20 |
| mRS before stroke: 0 | Participants | 30 |
| mRS before stroke: 1 | Participants | 3 |
| mRS before stroke: 2 | Participants | 2 |
| mRS before stroke: 3 | Participants | 3 |
| Intracerebral hemorrhage (ICH) volume | milliliters | 30.3 (17.7 to 48.8) |
6. Primary Endpoint
The registry lists the primary outcome as Number of Participants With Modified Rankin Score (mRS) ≤ 3 or mRS > 3, measured over 180 days.
| Element | Registry entry |
|---|---|
| Result type | Count Of Participants |
| Measure of spread | not applicable |
| Unit | Participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants in each of two modified Rankin Score categories at 180 days: mRS ≤ 3 or mRS > 3. The mRS is used to assess global disability. A categorized endpoint makes the outcome a binary classification for each participant, rather than a continuous measurement: each participant is assigned to one of the two stated categories.
In general, a disability scale can provide a structured way to describe functional outcome after a serious neurological event. Grouping scores can make the result easier to summarize, but it also discards distinctions between scores within the same category. The clinical interpretation of a category depends on the threshold chosen and the scale’s meaning; the registry description identifies the categories but does not provide further justification for the cutoff.
The endpoint’s timeframe is 180 days. The record notes that one participant was lost to follow-up after 1 month. It does not report the number of participants in either 180-day category, how the missing 180-day status was handled, or a numerical estimate of the endpoint. Consequently, the endpoint definition is available, but the posted record does not show the primary outcome distribution.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
This is a descriptive registry of 38 participants receiving best medical management plus minimally invasive endoscopic surgery with the Apollo or Artemis System. It is not a randomized comparison. The registry record describes its objective as collecting additional safety, technical outcomes and clinical outcomes data, rather than establishing a comparative treatment effect.
The primary outcome is defined as the count of participants with mRS ≤ 3 or mRS > 3 at 180 days. The registry record does not report the count in either category. Thus, the endpoint definition alone cannot indicate the observed disability distribution, and no estimate of its precision can be assessed from the posted primary outcome information.
One participant was lost to follow-up after 1 month. The record does not report the approach used for missing outcome data or identify the analysis population for the 180-day endpoint. This matters because an outcome that is not observed cannot simply be assumed to match the outcomes of participants who remained under follow-up. Without a stated handling method or sensitivity analyses, the possible effect of missingness on the endpoint cannot be evaluated.
The registry lists safety counts for the group: 20 participants affected by serious adverse events among 38 at risk, 25 affected by other adverse events among 38 at risk, and 4 deaths. These counts describe events recorded in the registry group. They do not, by themselves, show whether events were caused by the procedure or device, and without a comparison group they cannot quantify excess risk relative to another treatment strategy. The record lists serious adverse event terms and percentages, but does not report the additional definitions or attribution details needed to interpret them as comparative risks.
Statistical precision cannot be judged from counts alone. A confidence interval, when reported, describes the range of values compatible with the data under the analysis assumptions; none is reported for the primary endpoint in the registry record. The record also lists 0 analyses. No inferential result or adjusted estimate is available to support a comparative claim.
Planning illustrations based on a stated fraction of an observed effect are not observed power and are not the registry’s design justification. The stated assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those assumptions concern hypothetical planning, whereas this registry is single-group. No sample-size justification for the registry is reported in the registry record.
9. Statistical Methods Explained
The study design determines what statistical conclusions are available. In general, a randomized comparison assigns participants to treatment groups in a way intended to support a causal contrast. This registry is listed as single-group, with allocation NA and no masking. It therefore describes outcomes among enrolled participants receiving the registry treatment but does not provide a randomized counterfactual group. Differences between outcomes observed in this group and outcomes in other settings cannot be attributed to treatment from this registry alone.
What does a binary endpoint mean?
The primary measure is a count of participants categorized by mRS at 180 days: mRS ≤ 3 or mRS > 3. A binary outcome has two possible categories for analysis. A count can communicate how many participants fall into a category, but interpretation also depends on the number assessed and how missing outcomes are handled. The category counts are not reported in the registry record. There is therefore no posted primary endpoint estimate from which to assess statistical precision or to compare the distribution with another group.
In general, a confidence interval expresses uncertainty around an estimated quantity under the assumptions of the statistical method. It is not a guarantee that the true value lies within the interval, and its width depends on the data and method. The registry record does not report a confidence interval for the primary endpoint. No interval or other uncertainty estimate should be inferred from the endpoint definition or the enrollment count alone.
Why does the comparison structure matter?
The registry has no separate control group. A single-group result can describe events and outcomes in the participants enrolled, but it cannot separate the treatment’s contribution from other factors that may be associated with outcome. The record identifies a concurrent INVEST Feasibility randomized controlled trial, but registry participants were those who did not qualify for that trial at active INVEST centers. That does not turn the registry into a randomized comparison, and no like-for-like control comparison is reported.
The record lists 8 outcome measures and 0 analyses. In general, analysis plans specify which outcomes and comparisons will be evaluated and how uncertainty will be quantified. The registry record does not report a statistical analysis plan, model specifications, covariate adjustments, interim analyses, or a sample-size justification. Their absence from the record means those methods cannot be assessed; they should not be inferred from the outcome list.
How should planning illustrations be read?
The stated sample-size assumptions describe planning illustrations computed from an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Such illustrations ask what sample size might be needed under specified assumptions for a hypothetical comparison. They are not evidence that the registry was designed or powered that way, and are not observed power. The registry itself is single-group, so equal allocation between two arms does not describe its enrollment structure. The observed-effect value and registry sample-size justification are not reported in the registry record.
In general, power is a property of a design under an assumed effect and statistical model; it is not a measure of how likely a finding is to be true after data are collected. Planning estimates are sensitive to the assumed effect and other design choices. Where the effect is taken from observed data, the illustration remains a planning exercise rather than a new confirmatory analysis.
What can the safety counts establish?
Counts of affected participants describe recorded events within the group. They are not automatically estimates of treatment-attributable risk. General safety interpretation also depends on how events were defined, whether each count refers to participants or events, timing, seriousness criteria, and attribution to treatment. The record supplies counts of participants affected and a list of common serious adverse event terms, but those additional interpretive details are not reported in the registry record. Since there is no control group, comparative safety effects cannot be estimated from these counts alone.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 8 outcome measures, including the primary 180-day mRS categories and secondary outcomes of mRS at 30 days and 90 days, length of hospital stay, and participants requiring VPS. The record lists 0 analyses. A statistical plan describing which outcomes were tested, how they were prioritized, or how multiplicity was handled is not reported in the registry record.
In general, when multiple outcomes or repeated comparisons are examined, the chance of finding at least one apparently notable result can increase. Methods for managing this issue depend on the planned analyses and the purpose of the study. No multiplicity procedure is reported in the registry record, and no inferential analyses are listed. The endpoint list should not be read as evidence that each outcome was formally tested.
The registry notes one participant lost to follow-up after 1 month. The method used to handle missing values, the number assessed at each outcome time, and the analysis population for each endpoint are not reported in the registry record. In general, missing-data assumptions matter when observed participants may differ from those whose outcomes are unavailable. No imputation method, sensitivity analysis, or missing-data assumption is reported.
The record does not report whether analyses followed an intention-to-treat principle or another defined population. Given the single-group registry design, the enrolled group and the analysis population cannot be assumed to be identical for every outcome without explicit reporting.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Patients With Brain Hemorrhage | 20 | 38 | 52.6% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Patients With Brain Hemorrhage | 4 of 38 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Patients With Brain Hemorrhage | 25 of 38 |
Most frequent serious adverse event terms
| Event term | Organ system | Patients With Brain Hemorrhage |
|---|---|---|
| Stroke | Nervous system disorders | 3 of 38 |
| Abdominal pain | Gastrointestinal disorders | 2 of 38 |
| Acute respiratory failure | Respiratory, thoracic and mediastinal disorders | 2 of 38 |
| Deep venous thrombosis | Vascular disorders | 2 of 38 |
| Pulmonary embolism | Vascular disorders | 2 of 38 |
| Acute hemorrhage | Nervous system disorders | 1 of 38 |
| Acute inflammatory demyelinating polyneuropathy | Nervous system disorders | 1 of 38 |
| Aspiration pneumonia/fever | Infections and infestations | 1 of 38 |
| C. diff infection | Infections and infestations | 1 of 38 |
| Cranioplasty infection | Infections and infestations | 1 of 38 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Patients With Brain Hemorrhage |
|---|---|---|
| Fever | General disorders | 4 of 38 |
| Acute kidney injury | Renal and urinary disorders | 3 of 38 |
| Hypernatremia | Investigations | 3 of 38 |
| Urinary tract infection | Infections and infestations | 3 of 38 |
| Hypertension/hypertensive episode | Vascular disorders | 2 of 38 |
| Seizure | Nervous system disorders | 2 of 38 |
| Stroke | Nervous system disorders | 2 of 38 |
| Abdominal distension | Gastrointestinal disorders | 1 of 38 |
| Acute encephalopathy | Nervous system disorders | 1 of 38 |
| Ankle fracture | Injury, poisoning and procedural complications | 1 of 38 |
Serious events with the highest arm-level rate: stroke (7.9%), abdominal pain (5.3%), acute respiratory failure (5.3%), deep venous thrombosis (5.3%), pulmonary embolism (5.3%).
The registry lists 20 participants affected by serious adverse events among 38 at risk, and 25 participants affected by other adverse events among 38 at risk. It also lists 4 deaths. These are counts from the registry group, not comparisons against a control group. The record does not establish whether each event was judged related to the surgery or device.
The listed serious adverse event terms include Stroke (7.9%), Abdominal pain (5.3%), Acute respiratory failure (5.3%), Deep venous thrombosis (5.3%), Pulmonary embolism (5.3%), and Acute hemorrhage (2.6%). These percentages are quoted as listed in the registry record. The record does not report the denominator or calculation details for each term, whether terms can overlap within participants, or event timing and treatment attribution.
In general, safety counts describe what was recorded; they do not by themselves establish causality or comparative risk. Without a like-for-like comparator, the counts cannot show whether the frequency differs from another treatment strategy. The registry record does not report further definitions or analyses needed to make that comparison.
12. What the Result Does, and Does Not, Mean
The registry contributes prospective multicenter observations about participants with brain hemorrhage who received best medical management plus minimally invasive endoscopic surgery using the Apollo or Artemis System. Its stated aim was to provide additional safety, technical outcomes and clinical outcomes data for adults with supratentorial hemorrhage who did not qualify for the concurrent INVEST Feasibility randomized controlled trial at active INVEST centers.
The posted record identifies the primary clinical outcome and its 180-day timeframe, but does not report the number of participants in either mRS category. It therefore does not show the observed 180-day disability distribution. The record also lists adverse-event counts and common serious event terms, which describe the recorded safety experience of this group but do not establish whether an event was caused by treatment.
The single-group design is central to interpretation. In general, a treatment effect requires a comparison that can distinguish outcomes under one strategy from outcomes under an appropriate alternative. This registry has no separate control arm, and the record explicitly notes that arms are not a like-for-like control comparison. It cannot by itself establish a comparative benefit or harm.
The missing 180-day outcome information and the one participant lost to follow-up after 1 month further limit interpretation. The registry record does not report how missing data were handled, nor does it provide the primary endpoint analysis or uncertainty estimates. Readers should therefore distinguish the registry’s stated objectives and outcome definitions from results that are actually reported.
The sample-size planning assumptions are also separate from findings. Planning illustrations based on an observed effect do not constitute observed power, and they are not evidence of the registry’s original design rationale. Overall, the record describes a completed observational registry and some safety counts, while leaving key details for evaluating the primary clinical outcome and comparative effects unreported.
13. Why This Trial Matters Statistically
This registry is statistically useful to consider because it makes the distinction between collecting outcomes and estimating a treatment effect especially clear. A prospective multicenter registry can record clinical outcomes and safety events in a defined group. But without a suitable comparison group, those observations do not establish what would have happened to similar participants under another treatment strategy.
The primary endpoint illustrates another important principle: an outcome definition is not the same as a reported result. The record specifies mRS categories at 180 days, but does not report category counts. A reader therefore cannot assess the observed distribution or its precision from the posted primary outcome information. Reporting counts, denominators, missingness, and uncertainty would be necessary for a fuller statistical interpretation.
The safety information also shows why event counts need context. Counts of participants affected help describe the registry experience, but attribution, definitions, timing, and a comparator matter when asking whether treatment changed risk. The listed serious adverse event terms are not a substitute for a comparative safety analysis.
Finally, planning assumptions should not be mistaken for properties of the completed registry. A hypothetical two-arm sample-size illustration does not convert a single-group registry into a two-arm trial, nor does it show observed power. Keeping design, outcome reporting, safety description, and planning calculations separate prevents claims from extending beyond what the record can support.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The principal limitation is the single-group registry design. Allocation is listed as NA, masking as none, and there is no separate control group. As a result, the registry cannot provide a randomized estimate of the effect of the procedure compared with another strategy.
The record defines a 180-day primary mRS endpoint but does not report the numbers in either category or an analysis estimate. Although the registry lists 8 outcome measures, it lists 0 analyses. The statistical analysis plan, including any adjustment strategy, model choices, or interim analyses, is not reported in the registry record.
One participant was lost to follow-up after 1 month. The record does not report how this missing outcome information was handled, the number assessed at each timepoint, or any sensitivity analysis. The analysis population for the outcomes is also not reported in the registry record.
Safety reporting includes affected-participant counts and selected serious adverse event terms, but definitions, event timing, attribution, and term-specific denominator details are not reported in the registry record. The lack of a comparison group limits interpretation of the safety counts as relative risks.
The registry’s enrollment was 38. A sample-size justification for the registry is not reported in the registry record. The stated planning assumptions concern illustrations based on an observed effect and a two-arm comparison; they should not be interpreted as the registry’s design rationale or observed power.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: INVEST-REGISTRY: Minimally Invasive Endoscopic Surgical Treatment With Apollo/Artemis in Patients With Brain Hemorrhage — NCT02661672.
- Registry record last updated 2025-06-04; status last verified 2025-05.
- Results first posted 2025-06-04.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
INVEST-REGISTRY (NCT02661672) is a completed prospective multicenter, single-group registry of minimally invasive endoscopic surgery with Apollo or Artemis for supratentorial brain hemorrhage. The record lists 38 enrolled participants, no masking, and allocation and phase as NA. Participants received best medical management plus surgery and device-assisted clot evacuation.
The primary endpoint is the number of participants with mRS ≤ 3 or mRS > 3 at 180 days. The record notes one participant lost to follow-up after 1 month, but does not report primary endpoint category counts or an analysis. It lists 8 outcome measures and 0 analyses.
Safety counts include 20 participants affected by serious adverse events, 25 affected by other adverse events, and 4 deaths, among 38 at risk for each adverse-event group. The registry does not provide a control group for comparative interpretation.